Resumen
AbstractRubber (Hevea brasiliensis) one of the main plantation crops in Sri Lanka is the onlyplant species cultivated commercially for natural rubber harvesting. Novel systems forharvesting have been introduced but spatial distribution of photosynthetic potentialdetermining key factor for sustainable cultivation has not been properly explored. Use of suchtechniques such as Satellite Remote Sensing (RS) and Geographic Information System (GIS)to analyse spatial and biological factors related to the productivity of rubber plantation withdifferent harvesting systems is the main objective of the present study.Quikebird high resolution satellite images were used for RS analysis. Chlorophyllcontent of rubber leaves was measured using a SPAD-502 chlorophyll meter. Chlorophyllcontent and satellite images were analysed using GIS and spatial statistical methods todetermine the variation in different harvesting systems. Yield data were collected from thestudy site and yield parameters were correlated with chlorophyll content and NormalizedDifference Vegetation Index (NDVI) values. Results revealed all systems exhibitedpromising yield performance without significant deviation but slightly higher yield perhectare per year (YPH) and dry rubber content of latex (DRC) were recorded in quarter spiralbased once in three days (S/3 d4) and weekly (S/2 d1 2d7) harvesting systems. Chlorophyllcontent and rubber yield showed direct correlation in all systems. NDVI vs chlorophyllshowed positive correlation r2=0.65 and spatial distribution of chlorophyll and NDVI valuesdemonstrated sound physiological status of plants across the plantation with differentharvesting systems. Cost effective LIH systems showed better production trenddemonstrating relatively higher yield while reducing tapping cost and labour. Satellite basedremote sensing technique is an easy and efficient tool to estimate productivity of rubberplantation over a large area.Keywords: Chlorophyll, NDVI, harvesting, Remote Sensing, Rubber.